Introducing Emacs agent-shell (powered by ACP) (xenodium.com)

Emacs developer David (author) announced agent-shell, an Emacs-native interactive shell powered by acp.el — an Emacs Lisp client for the Agent Client Protocol (ACP) — that lets you interact with AI agents from a normal comint-mode buffer. Because it speaks ACP, agent-shell is agent-agnostic: switching between backends is just a matter of configuring the comms process (the post gives concrete examples for Gemini CLI and Claude Code). The package includes tooling like a traffic inspector (M-x agent-shell-view-traffic), a quick diff buffer UI, and the ability to save and replay recorded ACP traffic so you can develop and debug without repeatedly hitting paid APIs. Why it matters: ACP provides a common protocol to unify agent integrations, and bringing that into Emacs unlocks a consistent, in-editor agent experience for users and a reusable foundation for package authors. Technical highlights include using comint-mode for line/char I/O, acp-make-client/authenticate-request hooks for per-agent setup, partial implementation of the ACP schema in acp.el, and traffic replay to simulate agents during development. Both agent-shell and acp.el are available on GitHub as early-stage projects; the author notes incomplete schema coverage, invites contributions, and mentions cost pressures when developing against paid agents.